T-Mobile's latest offer for BlackBerry users seemed to be successful for everyone but BlackBerry.

According to TmoNews, T-Mobile's BlackBerry trade-in campaign resulted in 94 percent of old BB devices being traded for smartphones made by the company's competitors. It isn't clear exactly how many customers participated in the promotion.

Last month, T-Mobile presented a $200 trade-in offer for BlackBerry users that aimed to get them an iPhone for a great price. This led to a lot of fuss from BlackBerry fans and BlackBerry CEO John Chen, who called the promotion "inappropriate and ill-conceived."

T-Mobile tried to make it right by offering an extra $50 for users who decided to trade-in an old BlackBerry device in favor of a new one like the Z10 or Q10.

However, that extra $50 didn't seem to make much of a difference. A vast majority of old BlackBerry trade-ins ended up favoring other brands.

The offer ended today, and T-Mobile noted in an internal memo that the promo led to a 15x increase in BlackBerry trade-ins.

BlackBerry really didn't need to lose any extra customers at this time, considering the company is already having major troubles.

To make matters worse, fewer than half as many BlackBerry Enterprise Servers (BES) were in use as there were three years previous, and market capitalization had fallen from $83 billion USD in mid-2008 to a mere $3 billion USD late last year.

Overall, BlackBerry devices represented less than 1 percent of global smartphone shipped in the final quarter of last year.

But Chen remains positive and is looking to turn his company around. Chen -- BlackBerry's third CEO in just two years -- said he will focus on the enterprise once again, which is what BlackBerry has traditionally done best.